The only living child of John Bowie has pleaded with her father to reveal the truth of what he did with her mother's body.
Brenda Boyd, the daughter of Roxlyn and John Bowie, told the NSW Supreme Court that she often felt like "the angry little girl that lost her mum."
"Tell me where her body is, show my mum some respect that she most definitely deserves," she said.
"It's all I want, just a final answer."
In October last year, John Bowie was found guilty of murdering his wife, Roxlyn.
He maintained his innocence for more than 40 years, telling police that he had returned from the pub to find his wife missing from their Walgett home while their two children were asleep in their beds.
Ms Boyd told the court that she and her brother, Warren, returned to Walgett over the years looking for their mother.
"We put out missing persons posters throughout the town and nearby towns around Walgett. We talked to the locals," she said.
"[We even took] shovels to dig areas that were suggested to us over the years.
"I'm screaming inside to know the truth, even though I think I know what happened to my beautiful mum."
Witness for the prosecution
Brenda Boyd was six years old, and Warren almost two, when she was put to bed by her mother for the last time on the night of June 5, 1982.
When she woke the next morning, her mother was gone.
A letter was later found, alleged to have been written by Roxlyn Bowie, stating she was "leaving her husband and children".
A second note with a similar message was received three days later. But, the crown prosecutor told the court that Mr Bowie had forced, or coerced, his wife to write the two letters before killing her.
Ms Boyd said it still pained her that her grandparents passed away "not knowing what happened to their Roxy".
"They always told Warren and I stories about our mum's childhood, and that our Mum loved us and would never have left us," she said.
Part of Ms Boyd's victim impact statement was written with her brother, Warren, before his death in 2016.
She described their childhood after Roxlyn's disappearance as unstable. The two siblings attended more than a dozen schools and bore witness to a "high level of violence" with Mr Bowie's subsequent partners.
During the trial, Ms Boyd shared her memories of the domestic violence she witnessed just days before her mother's disappearance. She claimed to have seen her father choke her mother and shove food down her shirt.
"He was choking her. She was yelling at him to stop. I remember holding onto her leg and yelling at my dad to stop," she said.
Former partners of Mr Bowie were also called as crown witnesses, including his second wife, Anne Archer.
Ms Archer told the court that she had received medical treatment for injuries to her "arms, fractured ribs, left leg" and that her top lip had to be "stitched up from being punched in the mouth".
While Roxlyn Bowie's body has never been found, the crown told the court that Mr Bowie most likely disposed of his wife's body by feeding her to pigs at the local piggery he had ties to in Walgett.
During the trial, six crown witnesses told the court that Mr Bowie had said "pigs don't leave any evidence, not even bones" after his wife's disappearance, with one recalling Mr Bowie said he was having trouble with the police but it was OK because "pigs don't leave any evidence".
Mr Bowie will be sentenced at a later date.
